Impact of Protein Representations on Drug-Target Affinity Prediction

Matija Marijan1, 2* and Ivan Tanasijević1

1 The Institute for Artificial Intelligence Research and Development of Serbia, Novi Sad, Serbia

2 School of Electrical Engineering, University of Belgrade, Belgrade, Serbia

matija.marijan [at] ivi.ac.rs

Abstract

Accurate and rapid prediction of the binding affinity between potential drug candidates and target proteins can significantly hasten the drug discovery and development process. Utilizing artificial intelligence (AI) models to predict drug-target affinity (DTA) is an affordable and efficient strategy for sifting out undesirable molecules and identifying promising drug candidates. This approach allows researchers to focus on the most promising compounds for further in silico and wet lab experiments, thereby streamlining the overall workflow.

Advancements in AI research, such as the development and implementation of graph neural networks (GNN) and attention mechanisms, have significantly improved methods for processing small molecules as potential drug candidates. These developments now allow for very efficient and accurate DTA prediction, without the need for extensive protein processing resources. While this progress marks a significant step forward in computational drug discovery, models that heavily rely on efficient molecule processing may still lack the incorporation of highly specific protein information into their algorithms, which could be crucial for further improvement.

In this study, we present a comprehensive analysis of the impact of different protein representations on the accuracy of DTA prediction using two datasets, by implementing and modifying AI models that are based on GNNs and large language models (LLM).

Motivated by the intuitive resemblance between traditional motif search methods for protein sequence analysis and conventional one-dimensional convolution in AI signal processing, we propose a protein representation model based on transposed convolutional neural network (NN) layers. Preliminary results indicate that such embeddings improve the overall affinity prediction accuracy, compared to similar models from the literature. Additionally, implementing LLMs to generate protein embeddings independently of other NN layers has demonstrated potential to significantly enhance the accuracy of predicting drug-target pairs that have a very low or unmeasurable affinity.

Keywords: drug-target affinity, protein embeddings, graph neural networks, large language models, motif search